Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety. The description adds behavioral context such as end-of-day data, investment disclaimer, and no API key requirement, which goes beyond annotations but does not disclose any further limitations or side effects. The bar is lower given annotations, and the added context is useful but not extensive.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single dense paragraph with semicolon-separated section explanations. It is packed with information but organized logically, front-loading the purpose. While long, it avoids redundancy and each phrase serves a purpose, making it appropriately structured for a multi-section tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (9 sections, 2 optional parameters) and lack of an output schema, the description provides a fairly complete overview: it lists all sections, explains what each returns, notes the code requirement for the stock section, and states end-of-day basis and the no-key requirement. It is sufficient for an agent to understand the tool's scope, though exact output formats are not detailed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description must compensate. It explains the 'section' parameter by listing all enum values with brief descriptions (e.g., temperature as fear/greed 0-100, stock requiring a code and providing valuation scores). The 'code' parameter is only explained in the context of the stock section, leaving ambiguity for other sections. This adds meaning beyond the schema but does not fully clarify all parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool provides calculated market insights for the Korean market, listing nine specific sections (temperature, breadth, signals, sectors, earnings, calendar, disclosures, stock, all). It is specific about the resource and what it returns, though it does not explicitly distinguish itself from sibling tools like market_indicators or market_map.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides some context (e.g., '종가 기준' meaning end-of-day basis, '투자 권유 아님' meaning not investment advice, and 'No key needed') but does not state when to use this tool versus alternatives. There is no explicit guidance on selection criteria or exclusions relative to sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.